1. Field of the Invention
The present invention relates to a component mounting apparatus for mounting a large number of components such as, typically, electronic components, and more particularly, it relates to a component mounting apparatus oriented to energy-saving.
2. Discussion of the Related Art
As equipments for producing boards with a large number of components mounted thereon, there are screen printer, component mounting apparatus, reflow soldering and the like, and it is often the case that these machines are connected by transfer devices to construct a board production line. Of these machines, component mounting apparatuses are provided with a component mounting head (component picking member) for picking components from a component supply device to mount the components on a board and a head drive mechanism for driving the component mounting head. The head drive mechanism is provided with two horizontally movable members which are respectively movable in two orthogonal directions for moving the component mounting head to desired positions over the component supply device as well as over the board. Further, the head drive mechanism is provided with a vertical movable member for vertically moving the component mounting head to draw and mount components. Further, it is conventional that respective motors are provided and are controlled by a control section to drive the three moving members independently.
In component mounting apparatuses of this kind, the moving speed of each moving member has been increased more and more for high production efficiency and reduction in the time taken. Further, shortening the moving time has been sought in such a way that the component mounting head is not moved to turn sharply at right angles but is moved to draw a curve locus called “arch motion”. In a mounting component mounting device disclosed by the present assignee in JP 2008-311476 A, the device in an embodiment is provided with an X-axis slider and a Y-axis slider to enable free movements in a horizontal plane. Further, a nozzle holder (component mounting head) is able to perform the rotational (R-axis) motion and the vertical (Z-axis) motion as simultaneous operations (overlap operation). In such position control and posture control, a control section performs a control that it decelerates and stops a certain motor while starting and accelerating another motor.
In recent years, a preventive measure against the global warming has become an important theme which is to be attacked not only in a board production industry but also in all of the industrial world. An energy recycling method disclosed in JP 2001-37080 A takes managing regenerative energy in a group of machines as a solution to the problem of reducing the energy consumption in the whole of a factory. Further, as specific measures. there is disclosed a DC common link which makes a common connection of direct current power supplies for servo-driver units of the respective machines. Also in component mounting apparatuses, not only the aspect of production efficiency but also the aspect of energy-saving tends to be recognized as one item for performance evaluation. Accordingly, it is required to cope with the reduction in carbon dioxide emission by developing a component mounting apparatus which is of being as energy-saving as possible.
However, in the prior art component mounting apparatus exemplified in the first-mentioned Japanese application, the regenerative electric power which is generated when a motor is decelerated and stopped has been wasted by being converted into heat at regenerative resistances provided in a power supply section. That is, the regenerative electric power has not been utilized usefully and effectively, which is unfavorable from the viewpoint of energy-saving. On the other hand, the energy recycling method disclosed in the second-mentioned Japanese application is a technology which covers machine groups throughout the factory, and therefore, is difficult to use in the form specialized in utilizing regenerative electric power in a component mounting apparatus.
Further, in component mounting apparatuses, the vibration occurring on a base increases with an increase in the moving speed of each moving member. Moreover, where a plurality of moving members are simultaneously accelerated in the same direction, the reaction acting on the base is doubled to further increase the vibration. The increase in vibration is liable to affect the operation accuracy of the component mounting apparatus and hence, may give rise to a problem that causes a deterioration in accuracy of the boards produced by the apparatus.